Shielded telephone plug



Dec. 25, 1928. 1,696,657

A. M. TROGNER ET AL SHIELDED TELEPHONE PLUG Filed Jan. 24, 1927 Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

ARTHUR M. TROGNER, OF TAKOMA PARK, MARYLAND, AND THOMAS MGL. DAVIS, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNORS T WIRED RADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SHIELDED TELEPHONE PLUG.

Application filed January 24, 1927. Serial No. 163,046.

Our invention relates broadly to telephone plugs and more particularly to a. construction of electrostatic-ally shielded telephone plug for signal receiving circuits.

One of the objects of our invention is to provide an electrostatically shielded plug connector for the telephone circuit of a signal receiving apparatus whereby a standard construction of telephone plug may be effectively shielded against stray electrostatic charges or electromagnetic lines of force which would normally tend to establish a coupling with other portions of the signal receiving circuit for the setting up of interference and other undesirable noises.

Another object of our invention is to provide a construction of metallic shield into which the standard form of telephone plug may be inserted for the establishment of an electrostatic shield throughout the length of the plug connector and to which the flexible metallic shield of the telephone conductors may beconnected.

Still another object of our invention is to provide a construction of electrostatic shield for the conductors within a telephone plug where the shield may be engaged or disengaged with a locking block adjacenta telephone jack by a partially rotativemovement enabling the telephone plug and attached electrostatic shield to be electrical ly connected with or removed from the standard telephone jack.

Our invention will be more clearly understood from the specification hereinafter following by reference to the accompanying drawings, wherein: Figure 1 is a cross-seetional view taken through the electrostatic shield for the telephone plug of our invention illustrating the shield assembled with respect to the plug; Fig. 2 is a cross-sectional viewshowing the electrostatic shield locked in operative position for the reception of signals; Fig. 3 illustrates the electrostatic-ally shielded telephone plug rotated to a position wherein the electrostatic shield and the plug enclosed thereby may be removed from the telephone jack; Figs. at and illustrate modified forms of-the shielded telephone plug of our invention; and Fig. 6 is a view of the electrostatic shield removed from the telephone plug.

Heretofore, in the art, it has been customary to provide a flexible electrostatic shield for the conductors of a telephone headset.

This shield has normally terminated adjacent the ends of the telephone conductors and no provision has been made for preventing electrostatic and electromagnetic couplin between the free ends of the telephone lea s or the portions of the conductors and connecting means within the usual telephone plug and cooperating jack. Our present invention provides a construction of shield which may be positioned around the usual telephone plug for preventing the detrimental eifects of electromagnetic or electrostatic coupling with portions of the amplification circuits to which the telephone jack is normally connected. The construction of the shield is such that a standard form of telephone plug may be inserted within the shield and then the shield moved into position with respect to signal receiving apparatus for the establishment of circuit connections between the plug and jack.

Referring to the drawings in more detail, reference character 1 designates the flexible electrical conductors which may extend from a telephone headset, the conductors comprising the telephone leads 2 which are encased by a flexible electrical shield terminating in a connecting member 3. The conductors 2 pass into the telephone plug 4 having connecting portions 5 and 6 for engaging the usual spring connector portions 7 and 8 of telephone jack 9. The telephone jack 9 is mounted by an assembly of screw threaded bushings 10 within the signal receiving apparatus which may be encased by a metallic shield 11. Extending adjacent the front of the shield or panel 11, we provide a locking block 12 which is apertured at 14 to receive the telephone plug with its metallic shield in position when the. block is pushed into the jack 9. The insulated body portion of the plug 4 is encased by the readily removable shield 15. This shield 15 is spun or disposed inwardly at one end as represented at 16 and provided with an interiorly positioned coil spring 17 adjacent the opposite end. The plug 4 may be pushed into the interior of the shield 15 and constantly urged toward its end thereof by means of the spring 17. This spring has one end anchored to the electrostatic shield 15 as represented at 19, while the other end 18 enters a recess in the plug 4 and is anchored into the material thereof. The anchor 19 also provides a connecting means for the electrostatic shield connected with a conductor 3 and surround ing the telephone conductors 2. The telephone plug is thereby prevented from rotating by reason of the restraining action of the spring 17 upon the body of the plug 4. The shield 15 has a plurality of rectangular slot-s cut in the front end thereof as represented at 20 which are arranged to register with a spring member 21 operative in slot 22 of the block 12' which is secured adjacent the met-allic shield 11 of the signal receiving apparatus. When the shielded plug is inserted, this spring 21 rides over the spun over part 1d of the plug as shown in Fig. 3. Upon rotating the plug, the spring 21 snaps down lnto one of the'slots 20 looking the plug in place as represented in Fig. 2. The coil spring 17 constantly urges the shield outwardly and 1nto pressed engagement with the side of the flat spring 21 making constant contact wlth the plug shield. In order to remove the plug, the fiat spring is raised by rotation of the slneld out of one of the slots 20 enabling the plug to be pulled out of the jack.

In Fig. 4, we have shown a standard form of telephone plug 4 which is inserted within shield 15 and confined therein by means of a bolt member 23 against the action of coil spring 24.. The belt member 23 also serves as an anchor at 19 for the shield conductor 3. In Fig. 5, we have illustrated another modified construction of shielded telephone plug where the shield 15 is secured with respect to the body of the plug 4 by means of screw members 25 which pass through the shield 15 and enter the material of the plug 4. One of the screw members serves as an anchor at 19 for one end of the electrostatic shield which surrounds the conductors.

We have found the shielded plug of our invention very effective for securing required operation of sensitive electron tube amplifiers in preventing the noises encountered by the feed back of energy from various parts of the circuits of the amplification system.

The shield may be constructed in a variety of forms as will be apparent to those skilled in the art, and we desire that it be understood that the embodiments of our invention which we have illustrated are not to be considered as limiting the invention but that our invention contemplates all modifications of the construction within the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States is as follows: I g

,1. An electrical connector comprising a supporting member, a telephone plug arranged to cooperate with a telephone jack, an insulated member carried by said supporting member and surrounding one end of said jack, a cooperating body portion for said plug; telephone conductors extending into said cooperating body portion, and an electrostatic shield substantially enclosing the insulated body portion of said telephone plug and connected to ground for preventing electromagnetic or electrostatic coupling with conductors extending into said body portion and means carried by said insulated member for locking said plug in said jack.

2. In a telephone plug and ja k a supporting pane-l, an insulated block e i'ried by said panel, a telephone plug comprising a body portion, a pair of conductors extending into said body portion, said conductors beingsubsta-ntially enclosed by an electrostatic'shield to a position adjacent the body portion of said telephone plug, a metallic casing enclosing the body portion of said telephone plug and connected with the shield around said conductors for establishing a connection to ground, said plug being insertable through said insulated block, a jack positioned behind said panel for receiving said plug and means carried by said block for locking said plug within said jack. I

3. In a telephone plug and jack for establishing connection between a telephone circuit and an amplification circuit, a supporting panel, ablock member carried by said panel, a 'ack supported on said panel opposite said lock member, a telephone plug arranged to be inserted into said jack, said telephone plug being provided with a body portion with a pair of telephone conductors extending into said body portion, said conductors being substantially shielded to a position adjacent said telephone plug and a metallic casing arranged to yieldingly en gage and enclose the body portion of said telephone plug and provide an electrostatic shield around said telephone plug as a continuation of the electrostatic shield around said conductors and means carried by said block member for engaging the body port-ion of said plug and locking said plug within said jac 4. In a telephone plug and jack for establishing connection between an amplification circuit and a telephone circuit a supporting panel, a telephone jack carried by said panel, a socket member mounted on said supporting panel adjacent said jack, said telephone plug including a body portion into which the conductors of thetelephone circuit extend, a flexible electrostatic shield surrounding said conductors to a position adjacent the body portion of said plug, and a metallic shield surrounding the body portion of said plug and forming a continuation of said flexible electrostatic shield, said metallic shield being arranged to enter said socket member for establishing a'connection to ground and serving to establish an electrostatic shield throughout the length of said conductors.

5. In a telephone plug and jack, a panel member, a bushing mounted adjacent the panel member, a telephone jack carried by said panel member, a shielded telephone plug insertable through said bushing into said telephone jack and locking means carried by said bushing for locking said telephone plug in engagement with said telephone jack.

6. A telephone plug and jack, comprising a shielded telephone jack, a shielded telephone plug, a bushing positioned around said telephone ack into which said shielded telephone plug may be inserted or removed, said shielded telephone plug being angularly shiftable or disengaged from said telephone jack by partial rotative movement.

7 A telephone plug and jack, comprising a shielded telephone jack, a bushing positioned adjacent said telephone jack and adapted to receive a shielded telephone plug, said shielded telephone plug having a plurality of recesses in the end thereof adj aeent said shielded telephone jack and latching means extending into the recesses of said plug for loeating said plug in engagement With said jack.

In testimony whereof we afiix our signatures.

about the axis of said plug in said bushing and locking means carried by said bushing whereby said telephone plug may be engaged ARTHUR M. TROGNER. THOMAS MoL. DAVIS. 

